The fruit of the Genus Vitis is prized for its attractive appearance, firm texture, and flavor provided during fresh table grape consumption, and for the qualities needed for the production of quality juice or wine. However, it is well known that the shelf-life in which quality is maintained for the inevitably perishable freshly-harvested grapes has often tended to be relatively short, e.g., often approximately 14 to commonly less than 30 days depending on the packaging and storage techniques. This has necessitated prompt utilization by the grape consumer immediately following what is sometimes a brief time window for optimum grape harvest. It is recognized that consumers of fresh table grapes can be expected to demand a quality overall appearance, flavor, pliable green stems, and firm texture at the time of purchase, and at the time for consumption soon thereafter. This often translates into a minimum time window for the provider of freshly-harvested grapes to place the grapes on the market following the time for optimum harvest. The required transportation time and mode of transport to the point of sale or consumption further must be taken into consideration.
Various techniques have been proposed in the past to seek to extend the shelf life of freshly-harvested grapes. These have sometimes involved the lowering of the temperature during storage, and the use of high-speed circulating air along with periodic injections of sulfur dioxide in an effort to control fungal pathogens. Such high-speed circulating air often has caused the grape stems to dry out and for the fruit to wither somewhat. Also, the sulfur dioxide in view of its inherently corrosive nature often has caused fruit damage by weakening the skin of the grapes as well as weakening the integrity of the stems. The grapes accordingly become during such storage even further vulnerable to deleterious attack by fungal spores. Additionally, the sulfur dioxide has the propensity to bleach the skin of the grapes thereby rendering the lightening of the pigment of colored grapes and rendering white grapes somewhat orange in coloration. There continues to be a need to effectively extend the marketing period immediately following the optimum harvest time for grapes.
It is an object of the present invention to provide a specifically-defined improved process to prolong the storage life of grapes with the maintenance of quality for their intended end use.
It is a further object of the present invention to provide a specifically-defined improved process to prolong the storage life of table grapes with the maintenance of the sought-after grape qualities for human consumption, such as flavor, green pliable stems, firmness, and attractive appearance.
These and other objects and advantages of the invention will be apparent to those skilled in grape culture and in the handling and storage of freshly-picked grapes from the following description.